Answer:
In order to establish two of the many important applications that epidemiology has when assessing the delivery of health services, we must first know what epidemiology is. Epidemiology is the field of publich health that dedicates to the analysis and study of patterns, determinant factors, and ways of distribution of both disease and health in populations. As such it gives us the how, the when, the where and the who, of both diseases and health conditions. Without it, most healtchare systems in the world would be clueless as to how to intervene to ensure better health conditions for their populations.
As such, in total, there are seven important uses for epidemiology, but we will focus on two: studying the history of health and disease in populations, and examine the functioning of the available health services in nations, in order to assess if they meet the needs of the people.
In the first case, learning about the history of disease, and also health, will allow policy makers, both in the health fields and governmental areas, to make the best choices as to how to meet the health demands o their people, depending on their own history. Knowing what happened in the past regarding a certain health issue, such as HIV, or Ebola, can help policy makers see the rights and wrongs done in the past, the best and worst practices, and thus choose the best course of action to take if such a situation where to arise again. It most helps with preparedness.
In the second case, it is even more important because the process of examining health services offered worldwide, and in specific countries, will allow to establish policies of improvement, and make the correct choices as to how best to proceed to ensure not just immediate answers, but long-term solutions to a problem.
As said before, these are only two of the seven important impacts that epidemiology has on the correct application of health services.
